Burst Scheduling: Architecture and Algorithm for Switching Packet Video

We observed that variable bit rate (VBR) video, which is a sequence of encoded pictures, has very large rate fluctuations from picture to picture. In designing a new traffic model, we retain the basic notion of a flow but allow the flow rate to fluctuate. In particular, we introduce the concept of a burst which, in a video flow, is a sequence of packets that carry the bits of an encoded picture. We present the architecture of a class of packet switching networks, called Burst Scheduling networks, for carrying video, audio, and data traffic. The class is characterized by (i) use of virtual clock value as priority in scheduling, (ii) end-to-end delay and delay jitter guarantees provided to flows conforming to the new traffic model, and (iii) traffic flows (in particular, video flows) scheduled efficiently in bursts. Some experimental results are presented from a discrete-event simulation in which traces from several MPEG video sequences were used as video sources. 1 Introduction Real-ti..